Fig. 4

a Relationships between the measured sugar concentrations in the pseudostems (PS) and blades (BL) of the 15 ryegrass plants with wet chemistry data. There are positive relationships for measured high molecular weight sugar (HMW) (R² = 0.89, RMSE = 4.9 mg/g, slope = 0.34 ± 0.03), low molecular weight sugar (LMW) (R² = 0.50, RMSE = 5.6 mg/g, slope = 0.36 ± 0.10), and total (R² = 0.84, RMSE = 7.7 mg/g, slope = 0.32 ± 0.04). Total sugar concentration is 100–250 mg/g at the base of the sward (PS) and 40–100 mg/g at the top of the sward (BL). b Relationship between the measured total nitrogen % in the pseudostems (PS) and blades (BL) of 15 ryegrass plants with wet chemistry (R² = 0.83, RMSE = 0.14%, slope = 0.84 ± 0.11). Nitrogen concentration is 1.5–2.5% at the base of the sward (PS) and 2.5–4% at the top of the sward (BL)